[Dovecot] Sieve scripts

Hi

I have a simple sieve script to discard email with a certain string in the subject. I now need to beef this up a bit with the following:

if header :contains "subject" "A" and "B" and not "C" discard if header :contains "subject" "A" and "D" and not "C" discard else pass

Maybe my google skills are failing but I can't find much info on creating sieve scripts. Can anyone point me in the right direction to achieve this please ?

Cheers Nick .

__________ Information from ESET NOD32 Antivirus, version of virus signature database 4992 (20100401) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com